Certain features, such as the Extra Attack feature of the fighter, allow you to make more than one attack with this action. Each of these attacks is a separate roll and may target different creatures. You may move in between these attacks.
When you attack with a light melee weapon, you can use a bonus action to attack with your other hand (see the Offhand attackbonus action).
You may replace one of your melee attacks with a Grapple or a Shove.